Multiphase switching voltage regulator and controller

Abstract

The present disclosure relates to multiphase switching voltage regulators and controllers. A controller for a multiphase switching voltage regulator includes a first control loop and a second control loop. The first control loop has a first set of coefficients for implementing pulse width modulation (PWM) and a second set of coefficients for implementing pulse frequency modulation (PFM). The second control loop is configured to implement phase current balancing for the multiphase switching voltage regulator. In a first configuration, the first control loop is configured to implement PWM-based control of the multiphase switching voltage regulator using the first set of coefficients. In a second configuration, the first control loop is configured to implement PFM-based control of the multiphase switching voltage regulator using the second set of coefficients.

Description

Technical Field

[0001] This disclosure relates to multiphase switching voltage regulators and controllers. Background Technology

[0002] Voltage regulators typically require different types of modulation. The main modulation schemes used by voltage regulators are PWM (Pulse Width Modulation) and PFM (Pulse Frequency Modulation). Conventional voltage regulators are usually designed to implement one of PWM or PFM, rather than both, and therefore cannot switch from one modulation scheme to another, for example, when adding or dropping a phase.

[0003] Therefore, a more flexible voltage regulator design is needed that can support more than one modulation scheme. Summary of the Invention

[0004] According to an embodiment of a controller for a multiphase switching voltage regulator, the controller includes: a first control loop having a first set of coefficients for implementing pulse width modulation (PWM) and a second set of coefficients for implementing pulse frequency modulation (PFM); and a second control loop configured to implement phase current balancing for the multiphase switching voltage regulator, wherein in a first configuration, the first control loop is configured to use the first set of coefficients to implement PWM-based control of the multiphase switching voltage regulator, and wherein in a second configuration, the first control loop is configured to use the second set of coefficients to implement PFM-based control of the multiphase switching voltage regulator.

[0005] According to an embodiment of a voltage regulator system, the voltage regulator system includes: a multiphase switching voltage regulator; and a controller configured to control the multiphase switching voltage regulator. The controller includes: a first control loop having a first set of coefficients for implementing pulse width modulation (PWM) and a second set of coefficients for implementing pulse frequency modulation (PFM); and a second control loop configured to achieve phase current balancing for the multiphase switching voltage regulator, wherein in a first configuration, the first control loop is configured to use the first set of coefficients to achieve PWM-based control of the multiphase switching voltage regulator, and wherein in a second configuration, the first control loop is configured to use the second set of coefficients to achieve PFM-based control of the multiphase switching voltage regulator.

[0006] Those skilled in the art will recognize the additional features and advantages after reading the following detailed description and reviewing the accompanying drawings. Attached Figure Description

[0007] The elements in the accompanying drawings are not necessarily proportional to each other. Similar reference numerals refer to corresponding similar parts. Features of the various illustrated embodiments can be combined unless they are mutually exclusive. Embodiments are depicted in the accompanying drawings and described in detail below.

[0008] Figure 1 The diagram illustrates a voltage regulator system that includes a multiphase switching voltage regulator and a controller for controlling the multiphase switching voltage regulator.

[0009] Figure 2 The illustration shows different pulse width signaling techniques used for constant frequency (variable pulse width) modulation.

[0010] Figure 3 The illustration shows different pulse width signaling techniques used for constant on-time (variable frequency) modulation.

[0011] Figures 4 to 10 The illustration shows an embodiment of a first control loop and a second control loop included in a controller of a voltage regulator system. Detailed Implementation

[0012] The embodiments described herein provide a controller for a multiphase switching voltage regulator. The controller includes a first control loop and a second control loop. The second control loop implements phase current balancing for the multiphase switching voltage regulator. The first control loop supports different modulation schemes. For example, the first control loop may have a first set of coefficients for implementing pulse width modulation (PWM) and a second set of coefficients for implementing pulse frequency modulation (PFM). In a first (constant frequency) configuration, the first control loop uses the first set of coefficients to implement PWM-based control of the multiphase switching voltage regulator. In a second (constant on-time) configuration, the first control loop uses the second set of coefficients to implement PFM-based control of the multiphase switching voltage regulator. This allows the multiphase switching voltage regulator to be programmed to operate as either a pulse width modulator or a pulse frequency modulator, including during operation (in use), such as when the phase count changes. The same gate / circuit arrangements of the controller can be used to support both constant frequency modulation and constant on-time modulation, thus providing a low-cost, programmable, and flexible modulation method.

[0013] An embodiment of the controller and multiphase switching voltage regulator is described below with reference to the accompanying drawings.

[0014] Figure 1A schematic diagram of a voltage regulator system 100 is shown. The voltage regulator system 100 includes a multiphase switching voltage regulator 102 and a controller 104. The controller 104 controls the multiphase switching voltage regulator 102 by adjusting the output voltage Vout of the regulator 102 based on a reference voltage Vref. The multiphase switching voltage regulator 102 includes a power switch 106 (such as a Si or SiC power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), HEMT (High Electron Mobility Transistor), IGBT (Insulated Gate Bipolar Transistor), JFET (Junction Field-Effect Transistor), etc.). The power switch 106 is driven by a gate driver 108 under the control of the controller 104.

[0015] The switching voltage regulator 102 is multiphase because the power switches 106 are coupled to form separate phases, each contributing a total current I to the load. O Part of the load Figure 1 The resistor R is schematically illustrated in the diagram. L Under higher load conditions, most or all phases are operational. Controller 104 can deactivate (remove) one or more phases as load current demand decreases; for example, a single phase may be operational under the lightest load conditions.

[0016] Figure 1 The diagram shows a multiphase switching voltage regulator 102 configured for buck operation, wherein the inductor L O With capacitor C O The combination reduces voltage ripple on the output voltage Vout. The multiphase switching voltage regulator 102 can have other configurations, such as buck-boost, boost, etc.

[0017] The controller 104 for the multiphase switching voltage regulator 102 includes a first control loop 110 having a first set of coefficients for implementing pulse width modulation (PWM) and a second set of coefficients for implementing pulse frequency modulation (PFM). The controller 104 also includes a second control loop 112 that implements phase current balancing (current sharing) for the multiphase switching voltage regulator 102. For example, the second control loop 112 can adjust the pulse width or pulse frequency of each phase based on the sensed average phase current to balance the current in each phase. Other current balancing techniques can be implemented by the second control loop 112.

[0018] In a first (constant frequency) configuration, the first control loop 110 uses a first set of coefficients to implement PWM-based control of the multiphase switching voltage regulator 102. In a second (constant on-time) configuration, the first control loop 110 uses a second set of coefficients to implement PFM-based control of the multiphase switching voltage regulator 102. Depending on the configuration, the first control loop 110 can be a voltage and / or current-mode control loop implementing PWM or PFM. This configuration can be fixed during operation of the multiphase switching voltage regulator 102. Alternatively, the first control loop 110 can be programmable in either the first or second configuration during operation of the multiphase switching voltage regulator 102. In each case, the controller 104 uses the same control loop 110 to support both constant frequency modulation and constant on-time modulation.

[0019] Figure 2 The illustration shows different pulse width signaling techniques for constant frequency (variable pulse width) modulation, which can be implemented by a controller 104 for a multiphase switching voltage regulator 102. In the case of constant frequency modulation, the switching frequency and therefore the switching period are fixed, and the width of the modulation pulse "pw" is changed to achieve modulation. The modulation pulse can be a trailing edge, a leading edge, or a double edge, such as... Figure 2 As shown.

[0020] Figure 3 The illustration shows different pulse width signaling techniques for constant on-time (variable frequency) modulation, which can be implemented by a controller 104 for a multiphase switching voltage regulator 102. Using constant on-time modulation, the width of the modulation pulse "pw" is fixed, and the switching frequency Fsw is changed to achieve modulation. The modulation pulse can be a trailing edge or a double edge, such as... Figure 3 As shown.

[0021] Figures 4 to 10 The illustration shows embodiments of a first control loop 110 and a second control loop 112 included in a controller 104. Some embodiments use both voltage-mode control and current-mode control, while other embodiments use voltage-mode control instead of current-mode control.

[0022] exist Figure 4In the first control loop 110 of controller 104, a voltage-mode controller 200 and a current-mode controller 202 are included, and the first control loop 110 is shown configured in a first (constant frequency) configuration. The voltage-mode controller 200 may be, for example, a PID (proportional-integral-derivative) controller with poles, which generates a current control signal i_ctrl based on a voltage error signal V_err representing the difference between the reference voltage Vref and the output voltage Vout of the multiphase switching voltage regulator 102. In the first configuration, the current-mode controller 202 generates a pulse-width modulation adjustment signal pw_Δ using a first set of coefficients based on the current error signal i_err derived from the current control signal i_ctrl.

[0023] exist Figure 4 In the first control loop 110, a logic / circuit device 204 is included that divides the current control signal i_ctrl by the number of active phases "n" of the multiphase switching voltage regulator 102 to generate a per-phase current control signal i_ctrl_ph. The first control loop 110 also includes a logic / circuit device 206 that compares the per-phase current control signal i_ctrl_ph with a signal i_ph_avg representing the average current of all active phases of the multiphase switching voltage regulator 102 to generate a current error signal i_err.

[0024] The second control loop 112 includes logic / circuit device 208 that compares each phase current i_ph_n with a signal i_ph_avg representing the average current of all active phases to generate a per-phase current error i_ph_err. The second control loop 112 also includes a current balancing logic / circuit device 210 that generates a current balancing adjustment signal iba1_pw_adj for each active phase of the multiphase switching voltage regulator 102 to balance the phase current. According to this embodiment, the current control function is divided into two comparisons: one for comparing the phase control current with the average current, and another for comparing the average current with the phase current. This method requires only a single current control block 202 for the first control loop 110, which is the faster block. The phase balancing blocks 208, 210 can be slower. Even when using n phase balancing modules 210 in this embodiment, logic gates / circuit devices can be saved by reducing resolution and / or by using time-sharing (time-division multiplexing) logic.

[0025] If the controller 104 employs feedforward control, the first control loop 110 may include a logic / circuit device 212 that modifies the feedforward pulse width modulation signal ff_pw using a pulse width modulation adjustment signal pw_Δ and a current balance adjustment signal ibal_pw_adj generated by the second control loop 112 for each active phase of the multiphase switching voltage regulator 102, to generate a pulse width modulation signal pw_n for controlling each active phase of the multiphase switching voltage regulator 102 in a first configuration. For example, the feedforward pulse width modulation signal ff_pw may be a pulse signal, and the pulse width modulation adjustment signal pw_Δ and the current balance adjustment signal ibal_pw_adj determine how much the width of the pulse signal is adjusted to maintain regulation.

[0026] exist Figure 5 In the image, the first control loop 110 configured in a first (constant frequency) configuration is shown again. Figure 4 different, Figure 5 The first control loop 110 includes a logic / circuit device 300 that compares the current control signal i_ctrl with a signal i_tot representing the total current of all active phases of the multiphase switching voltage regulator 102 to generate a current error signal i_err. According to this embodiment, the first control loop 110 is omitted. Figure 4 The n-division block 204 shown simplifies the control loop logic and reduces the time delay in the fast path through the current-mode controller 202. The gain inside the current-mode controller 202 changes with the number of active phases n.

[0027] exist Figure 6 The image shows a first control loop 110 configured with a second (constant on-time) configuration. By comparison... Figure 4 and Figure 5 and Figure 6 It can be seen that controller 104 does not require different gate / circuit devices to support both constant frequency modulation and constant on-time modulation. Instead, the same voltage-mode controller 200 and current-mode controller 202 can be used to support both the first and second modulation configurations.

[0028] In the second (constant on-time) configuration, the current-mode controller 202 uses a second set of coefficients based on the current error signal i_err to generate a pulse frequency modulation adjustment signal t-step_Δ. If the controller 104 employs feedforward control, the first control loop 110 may include a logic / circuit device 212 that modifies the feedforward pulse frequency modulation signal ff_pw_t-step using the pulse frequency modulation adjustment signal t-step_Δ to generate a pulse frequency modulation signal t-step for controlling each active phase of the multiphase switching voltage regulator 102. The second control loop 112 may also include a logic / circuit device 400 that modifies the constant on-time “cot” for each active phase of the multiphase switching voltage regulator 102 based on the phase current imbalance ibal_pw_adj observed by the current balancing logic / circuit device 210 of the second control loop 112 to generate a pulse width modulation signal pw_n.

[0029] By interpreting the output of current control block 202 as a time step Δ ( Figure 6 The t-step_Δ is used instead of the pulse width Δ. Figure 4 and 5 In the context of pw_Δ), and by using the width of the feedforward pulse frequency modulation signal ff_pw_t-step as the constant on-time signal cot, Figure 5 The control structure shown can be used to implement constant on-time modulation. Because the control structure in... Figure 5 and Figure 6 The gain in the current-mode controller 202 is the same, so it can support modulation configurability (constant frequency or constant on-time) without large gate counting losses. The gain in the current-mode controller 202 can be changed, but the control structure and corresponding mathematics remain the same.

[0030] Constant frequency and constant on-time modulation can be mathematically related as follows: (1) (2) in dutyc It is the duty cycle in a constant switching frequency system. T It is the switching cycle. FF It is the feedforward pulse width. pwd It is the pulse width Δpw_Δ. r It is the rate or time step t-step. rd It is the time step Δt-step_Δ, and ON_t It is the nominal rate plus Δ change (e.g., how the time step changes from a normal time step of 1). pwd and FF The ratio equalsrd The ratio of r and FF / T or ON_t . r It is the nominal duty cycle.

[0031] As shown in equations (1) and (2), the change in time step alters the slope. For a switching frequency Fsw of 1000 clock cycles, controller 104 can start at 999 and count down to zero and repeat the process to generate a series of sawtooth ramp signals, for example, as Figure 2 As shown. Each sawtooth ramp signal corresponds to a (1) switching cycle, where each new pulse begins at each zero. Under constant on-time modulation, the ramp may not change uniformly by a step size from 999 to 0, but the controller 104 can dynamically change the step size (i.e., the ramp). For example, if a large error occurs, the controller 104 can implement a larger step size (e.g., 3 steps at a time), making the ramp steeper and the cycle smaller as the switching frequency Fsw increases. Because the time step size changes continuously with constant on-time modulation, the final switching frequency Fsw changes to give a change in duty cycle, for example, as Figure 3 As shown.

[0032] Figure 7 The diagram shows Figures 4 to 6 The block diagram shown is of the current-mode controller 202. The current-mode controller 202 is... Figure 7 The PI (proportional-integral) controller 500 is described. According to this embodiment, the first set of coefficients includes a first proportional coefficient P1 for the proportional term Kp of the PI controller 500 and a first integral coefficient I1 for the integral term Ki of the PI controller 500. The second set of coefficients includes a second proportional coefficient P2 for the proportional term Kp and a second integral coefficient I2 for the integral term Ki.

[0033] In a first (constant frequency) configuration, the PI controller 500 uses a first set of proportional coefficients P1 and integral coefficients I1 to generate a pulse width modulation adjustment signal pw_Δ based on the current error signal i_err. In a second (constant on-time) configuration, the PI controller 500 uses a second set of proportional coefficients P2 and integral coefficients I2 to generate a pulse frequency modulation adjustment signal t-step_Δ based on the current error signal i_err. For example, the PI controller 500 may include a first multiplexer logic gate 502 and a second multiplexer logic gate 504, wherein the first multiplexer logic gate 502 is used to select, between the first proportional coefficient P1 and the second proportional coefficient P2, as the proportional coefficient of the proportional term Kp of the PI controller 500, and the second multiplexer logic gate 504 is used to select, between the first integral coefficient I1 and the second integral coefficient I2, as the integral coefficient of the integral term Ki of the PI controller 500.

[0034] In one embodiment, the first scaling factor P1 is calculated as P / (Vin n), the first integral coefficient I1 is calculated as I / (Vin n), the second proportionality coefficient P2 is calculated as P / (Vout) n (swp), and the second integral coefficient I2 is calculated as I / (Vout) n swp), where n is the number of active phases of the multiphase switching voltage regulator 102, Vin is the input voltage of the multiphase switching voltage regulator 102, Vout is the output voltage of the multiphase switching voltage regulator 102, swp is the number of clocks in the switching period T, P is the programmed proportional term, and I is the programmed integral term.

[0035] Figure 8 The diagram illustrates a first control loop 110 configured in a first (constant frequency) configuration with only voltage-mode control. That is, the first control loop 110 includes a voltage-mode controller 200, but in... Figure 8 The current-mode controller 202 is omitted. In the first (constant frequency) configuration, the voltage-mode controller 200 generates a pulse-width modulation adjustment signal pw_Δ based on a voltage error signal Verr using a first set of coefficients. The voltage error signal Verr represents the difference between the reference voltage Vref and the output voltage Vout of the multiphase switching voltage regulator 102. The first control loop 110 may also include a logic / circuit device 212 that modifies the feedforward pulse-width modulation signal ff_pw using the pulse-width modulation adjustment signal pw_Δ and the current balance adjustment signal iba1_pw_adj generated by the second control loop 112 for each active phase of the multiphase switching voltage regulator 102 to generate a pulse-width modulation signal pw_n for controlling each active phase of the multiphase switching voltage regulator 102 in the first configuration.

[0036] Figure 9 The diagram shows Figure 8 The first control loop 110 is configured with a second (constant on-time) configuration. That is, the first control loop 110 includes a voltage-mode controller 200, but in Figure 9The current-mode controller 202 is omitted. In the second configuration, the voltage-mode controller 200 generates a pulse frequency modulation adjustment signal t-step_Δ based on the voltage error signal V_err using a second set of coefficients. In the second configuration, the first control loop 110 can use the pulse frequency modulation adjustment signal t-step_Δ to modify the feedforward pulse frequency modulation signal ff_pw_tstep to generate a pulse frequency modulation signal t-step for controlling each active phase of the multiphase switching voltage regulator 102. In the second configuration, the second control loop 112 can modify the constant on-time “cot” of each active phase of the multiphase switching voltage regulator 102 based on the phase current imbalance ibal_pw_adj observed by the current balancing logic / circuit device 210 of the second control loop 112.

[0037] Figure 10 The diagram shows Figure 8 and Figure 9 The block diagram shown is of a voltage-mode controller 200. The voltage-mode controller 200 is... Figure 10 The PID (Proportional-Integral-Derivative) controller 600 is described in this embodiment. According to this embodiment, the first set of coefficients includes: a first proportional coefficient P1 for the proportional term Kp of the PID controller 600, a first integral coefficient I1 for the integral term Ki of the PID controller 600, and a first derivative coefficient D1 for the derivative term Kd of the PID controller 600. The second set of coefficients includes: a second proportional coefficient P2 for the proportional term Kd, a second integral coefficient I2 for the integral term Ki, and a second derivative coefficient D2 for the derivative term Kd.

[0038] In the first (constant frequency) configuration, the PID controller 600 uses a first set of proportional coefficients P1, integral coefficients I1, and derivative coefficients D1 to generate a pulse width modulation adjustment signal pw_Δ based on the voltage error signal V_err. In the second (constant on-time) configuration, the PID controller 600 uses a second set of proportional coefficients P2, integral coefficients I2, and derivative coefficients D2 based on the voltage error signal V_err to generate a pulse frequency modulation adjustment signal t-step_Δ. For example, the PID controller 600 may include a first multiplexer logic gate 602, a second multiplexer logic gate 604, and a third multiplexer logic gate 606. The first multiplexer logic gate 602 is used to select the proportional coefficient of the proportional term Kp of the PID controller 600 between the first proportional coefficient P1 and the second proportional coefficient P2. The second multiplexer logic gate 604 is used to select the integral coefficient of the integral term Ki of the PID controller 600 between the first integral coefficient I1 and the second integral coefficient I2. The third multiplexer logic gate 606 is used to select the derivative coefficient of the derivative term Kd of the PID controller 600 between the first derivative coefficient D1 and the second derivative coefficient D2.

[0039] In one embodiment, the first scaling factor P1 is calculated as P / (Vin The first integral coefficient I1 is calculated as I / Vin, and the first derivative coefficient D1 is calculated as D / (Vin). n), the second proportionality coefficient P2 is calculated as P / (Vout) (swp), the second integral coefficient I2 is calculated as I / (Vout) (swp), and the second derivative coefficient D2 is calculated as D / (Vout) n swp), where n is the number of active phases of the multiphase switching voltage regulator 102, Vin is the input voltage of the multiphase switching voltage regulator 102, Vout is the output voltage of the multiphase switching voltage regulator 102, swp is the number of clocks in the switching period T, P is the programmed proportional term, I is the programmed integral term, and D is the programmed derivative term.

[0040] Although this disclosure is not limited thereto, the following numbered examples illustrate one or more aspects of this disclosure.

[0041] Example 1. A controller for a multiphase switching voltage regulator, the controller comprising: a first control loop having a first set of coefficients for implementing pulse width modulation (PWM) and a second set of coefficients for implementing pulse frequency modulation (PFM); and a second control loop configured to implement phase current balancing for the multiphase switching voltage regulator, wherein in a first configuration, the first control loop is configured to use the first set of coefficients to implement PWM-based control of the multiphase switching voltage regulator, and wherein in a second configuration, the first control loop is configured to use the second set of coefficients to implement PFM-based control of the multiphase switching voltage regulator.

[0042] Example 2. The controller according to Example 1, wherein during operation of the multiphase switching voltage regulator, the first control loop is programmable in either a first configuration or a second configuration.

[0043] Example 3. A controller according to Example 1 or 2, wherein the first control loop includes: a voltage-mode controller configured to generate a current control signal based on a voltage error signal, the voltage error signal representing the difference between a reference voltage and the output voltage of a multiphase switching voltage regulator; and a current-mode controller, wherein in a first configuration, the current-mode controller is configured to generate a pulse width modulation adjustment signal based on a current error signal derived from the current control signal using a first set of coefficients, wherein in a second configuration, the current-mode controller is configured to generate a pulse frequency modulation adjustment signal based on the current error signal using a second set of coefficients.

[0044] Example 4. According to the controller of Example 3, wherein, in a first configuration, a first control loop is configured to modify a feedforward pulse width modulation signal with a pulse width modulation adjustment signal and a current balance adjustment signal to generate a pulse width modulation signal for controlling each active phase of a multiphase switching voltage regulator, the current balance adjustment signal being generated by a second control loop for each active phase of the multiphase switching voltage regulator.

[0045] Example 5. A controller according to Example 3 or 4, wherein in a second configuration, a first control loop is configured to modify a feedforward pulse frequency modulation signal with a pulse frequency modulation adjustment signal to generate a pulse frequency modulation signal for controlling each active phase of a multiphase switching voltage regulator.

[0046] Example 6. A controller according to Example 5, wherein in a second configuration, a second control loop is configured to modify the constant on-time of each active phase of the multiphase switching voltage regulator based on the phase current imbalance observed by the second control loop.

[0047] Example 7. A controller according to any one of Examples 3 to 6, wherein a first control loop is configured to divide a current control signal by the number of active phases of a multiphase switching voltage regulator to generate a per-phase current control signal, and to compare the per-phase current control signal with a signal representing the average current of all active phases to generate a current error signal.

[0048] Example 8. A controller according to any one of Examples 3 to 7, wherein a first control loop is configured to compare a current control signal with a signal representing the total current of all active phases of a multiphase switching voltage regulator to generate a current error signal.

[0049] Example 9. A controller according to any one of Examples 1 to 8, wherein the first control loop includes a PI (proportional-integral) controller, wherein the first set of coefficients includes a first proportional coefficient for the proportional term of the PI controller and a first integral coefficient for the integral term of the PI controller, and wherein the second set of coefficients includes a second proportional coefficient for the proportional term and a second integral coefficient for the integral term.

[0050] Example 10. Based on the controller of Example 9, where the first proportional coefficient is calculated as P / (Vin) n), the first integral coefficient is calculated as I / (Vin n), the second proportionality coefficient is calculated as P / (Vout) n swp), and the second integral coefficient is calculated as I / (Vout). n swp), where n is the number of active phases of the multiphase switching voltage regulator, Vin is the input voltage of the multiphase switching voltage regulator, Vout is the output voltage of the multiphase switching voltage regulator, swp is the number of clock cycles in the switching period, P is the programmed proportional term, and I is the programmed integral term.

[0051] Example 11. A controller according to any one of Examples 1 to 10, wherein the first control loop includes a voltage-mode controller, wherein in a first configuration, the voltage-mode controller is configured to generate a pulse width modulation adjustment signal based on a voltage error signal using a first set of coefficients, wherein in a second configuration, the voltage-mode controller is configured to generate a pulse frequency modulation adjustment signal based on a voltage error signal using a second set of coefficients, the voltage error signal representing the difference between a reference voltage and the output voltage of a multiphase switching voltage regulator.

[0052] Example 12. According to the controller of Example 11, wherein, in a first configuration, a first control loop is configured to modify a feedforward pulse width modulation signal with a pulse width modulation adjustment signal and a current balance adjustment signal to generate a pulse width modulation signal for controlling each active phase of a multiphase switching voltage regulator, the current balance adjustment signal being generated by a second control loop for each active phase of the multiphase switching voltage regulator.

[0053] Example 13. A controller according to Example 11 or 12, wherein in a second configuration, a first control loop is configured to modify a feedforward pulse frequency modulation signal with a pulse frequency modulation adjustment signal to generate a pulse frequency modulation signal for controlling each active phase of a multiphase switching voltage regulator.

[0054] Example 14. A controller according to Example 13, wherein in a second configuration, a second control loop is configured to modify the constant on-time of each active phase of the multiphase switching voltage regulator based on the phase current imbalance observed by the second control loop.

[0055] Example 15. A controller according to any one of Examples 1 to 14, wherein the first control loop includes a PID (proportional-integral-derivative) controller, wherein the first set of coefficients includes: a first proportional coefficient for the proportional term of the PID controller, a first integral coefficient for the integral term of the PID controller, and a first derivative coefficient for the derivative term of the PID controller; and wherein the second set of coefficients includes: a second proportional coefficient for the proportional term of the PID controller, a second integral coefficient for the integral term of the PID controller, and a second derivative coefficient for the derivative term of the PID controller.

[0056] Example 16. Based on the controller of Example 15, where the first proportional coefficient is calculated as P / (Vin) The first integral coefficient is calculated as I / Vin, and the first derivative coefficient is calculated as D / (Vin). n), the second proportionality coefficient is calculated as P / (Vout) The second integral coefficient is calculated as I / (Vout). (swp), and the second derivative coefficient is calculated as D / (Vout) n swp), where n is the number of active phases of the multiphase switching voltage regulator, Vin is the input voltage of the multiphase switching voltage regulator, Vout is the output voltage of the multiphase switching voltage regulator, swp is the number of clock cycles in the switching period, P is the programmed proportional term, I is the programmed integral term, and D is the programmed derivative term.

[0057] Example 17. A voltage regulator system includes: a multiphase switching voltage regulator; and a controller configured to control the multiphase switching voltage regulator, the controller including: a first control loop having a first set of coefficients for implementing pulse width modulation (PWM) and a second set of coefficients for implementing pulse frequency modulation (PFM); and a second control loop configured to implement phase current balancing for the multiphase switching voltage regulator, wherein in a first configuration, the first control loop is configured to use the first set of coefficients to implement PWM-based control of the multiphase switching voltage regulator, and wherein in a second configuration, the first control loop is configured to use the second set of coefficients to implement PFM-based control of the multiphase switching voltage regulator.

[0058] Example 18. A voltage regulator system according to Example 17, wherein a first control loop includes: a voltage-mode controller configured to generate a current control signal based on a voltage error signal, the voltage error signal representing the difference between a reference voltage and the output voltage of a multiphase switching voltage regulator; and a current-mode controller, wherein in a first configuration, the current-mode controller is configured to generate a pulse width modulation adjustment signal based on a current error signal derived from the current control signal using a first set of coefficients, wherein in a second configuration, the current-mode controller is configured to generate a pulse frequency modulation adjustment signal based on the current error signal using a second set of coefficients.

[0059] Example 19. A voltage regulator system according to Example 17 or 18, wherein a first control loop includes a voltage-mode controller, wherein in a first configuration, the voltage-mode controller is configured to generate a pulse-width modulation adjustment signal based on a voltage error signal using a first set of coefficients, wherein in a second configuration, the voltage-mode controller is configured to generate a pulse-frequency modulation adjustment signal based on the voltage error signal using a second set of coefficients, the voltage error signal representing the difference between a reference voltage and the output voltage of a multiphase switching voltage regulator.

[0060] Example 20. A voltage regulator system as described in any of Examples 17 to 19, wherein a first control loop includes a PID (proportional-integral-derivative) controller, wherein a first set of coefficients includes: a first proportional coefficient for the proportional term of the PI controller, a first integral coefficient for the integral term of the PI controller, and a first derivative coefficient for the derivative term of the PI controller; and wherein a second set of coefficients includes: a second proportional coefficient for the proportional term of the PI controller, a second integral coefficient for the integral term of the PI controller, and a second derivative coefficient for the derivative term of the PI controller.

[0061] Terms such as "first" and "second" are used to describe various elements, regions, segments, etc., and are not intended to be limiting. Similar terms refer to similar elements throughout the specification.

[0062] As used herein, the terms “having,” “containing,” “including,” “comprising,” etc., are open-ended terms that indicate the presence of the stated element or feature but do not exclude additional elements or features. The articles “a,” “an,” and “the” are intended to include both plural and singular forms unless the context clearly indicates otherwise.

[0063] The expression "and / or" should be interpreted to encompass all possible combinations of conjunctions and disjunctive words, unless otherwise expressly stated. For example, the expression "A and / or B" should be interpreted to mean A but not B, B but not A, or both A and B. The expression "at least one of" should be interpreted in the same way as "and / or," unless otherwise expressly stated. For example, the expression "at least one of A and B" should be interpreted to mean A but not B, B but not A, or both A and B.

[0064] It should be understood that the features of the various embodiments described herein can be combined with each other unless otherwise specifically indicated.

[0065] Although specific embodiments have been shown and described herein, those skilled in the art will understand that various alternatives and / or equivalent implementations may be used to replace the specific embodiments shown and described without departing from the scope of the invention. This application is intended to cover any modifications or variations of the specific embodiments discussed herein. Therefore, the invention is defined only by the claims and their equivalents.

Claims

1. A controller for a multiphase switching voltage regulator, the controller comprising: The first control loop has a first set of coefficients for implementing pulse width modulation (PWM) and a second set of coefficients for implementing pulse frequency modulation (PFM). as well as The second control loop is configured to achieve phase current balance for the multiphase switching voltage regulator. In the first configuration, the first control loop is configured to use the first set of coefficients to implement PWM-based control of the multiphase switching voltage regulator. In the second configuration, the first control loop is configured to use the second set of coefficients to implement PFM-based control of the multiphase switching voltage regulator.

2. The controller of claim 1, wherein during operation of the multiphase switching voltage regulator, the first control loop is programmable in either the first configuration or the second configuration.

3. The controller according to claim 1, wherein the first control loop comprises: A voltage-mode controller is configured to generate a current control signal based on a voltage error signal representing the difference between a reference voltage and the output voltage of the multiphase switching voltage regulator; as well as Current-mode controller In the first configuration, the current-mode controller is configured to generate a pulse-width modulation adjustment signal based on a current error signal derived from the current control signal, using the first set of coefficients. In the second configuration, the current-mode controller is configured to generate a pulse frequency modulation adjustment signal based on the current error signal using the second set of coefficients.

4. The controller of claim 3, wherein in the first configuration, the first control loop is configured to modify the feedforward pulse width modulation signal with the pulse width modulation adjustment signal and the current balance adjustment signal to generate a pulse width modulation signal for controlling each active phase of the multiphase switching voltage regulator, the current balance adjustment signal being generated by the second control loop for each active phase of the multiphase switching voltage regulator.

5. The controller of claim 3, wherein in the second configuration, the first control loop is configured to modify the feedforward pulse frequency modulation signal with the pulse frequency modulation adjustment signal to generate a pulse frequency modulation signal for controlling each active phase of the multiphase switching voltage regulator.

6. The controller of claim 5, wherein in the second configuration, the second control loop is configured to modify the constant on-time of each active phase of the multiphase switching voltage regulator based on the phase current imbalance observed by the second control loop.

7. The controller according to claim 3, wherein, The first control loop is configured to divide the current control signal by the number of active phases of the multiphase switching voltage regulator to generate a per-phase current control signal, and to compare the per-phase current control signal with a signal representing the average current of all the active phases to generate the current error signal.

8. The controller according to claim 3, wherein, The first control loop is configured to compare the current control signal with a signal representing the total current of all active phases of the multiphase switching voltage regulator to generate the current error signal.

9. The controller of claim 1, wherein the first control loop comprises a proportional-integral (PI) controller, wherein the first set of coefficients comprises a first proportional coefficient for the proportional term of the PI controller and a first integral coefficient for the integral term of the PI controller, and wherein the second set of coefficients comprises a second proportional coefficient for the proportional term and a second integral coefficient for the integral term.

10. The controller of claim 9, wherein the first proportional coefficient is calculated as P / (Vin n), the first integral coefficient is calculated as I / (Vin n), the second proportionality coefficient is calculated as P / (Vout) n swp), and the second integral coefficient is calculated as I / (Vout). n swp), where n is the number of active phases of the multiphase switching voltage regulator, Vin is the input voltage of the multiphase switching voltage regulator, Vout is the output voltage of the multiphase switching voltage regulator, swp is the number of clocks in the switching cycle, P is the programmed proportional term, and I is the programmed integral term.

11. The controller of claim 1, wherein the first control loop comprises a voltage-mode controller, wherein in the first configuration, the voltage-mode controller is configured to generate a pulse width modulation adjustment signal based on a voltage error signal using the first set of coefficients, wherein in the second configuration, the voltage-mode controller is configured to generate a pulse frequency modulation adjustment signal based on the voltage error signal using the second set of coefficients, the voltage error signal representing the difference between a reference voltage and the output voltage of the multiphase switching voltage regulator.

12. The controller of claim 11, wherein in the first configuration, the first control loop is configured to modify the feedforward pulse width modulation signal with the pulse width modulation adjustment signal and the current balance adjustment signal to generate a pulse width modulation signal for controlling each active phase of the multiphase switching voltage regulator, the current balance adjustment signal being generated by the second control loop for each active phase of the multiphase switching voltage regulator.

13. The controller of claim 11, wherein in the second configuration, the first control loop is configured to modify the feedforward pulse frequency modulation signal with the pulse frequency modulation adjustment signal to generate a pulse frequency modulation signal for controlling each active phase of the multiphase switching voltage regulator.

14. The controller of claim 13, wherein in the second configuration, the second control loop is configured to modify the constant on-time of each active phase of the multiphase switching voltage regulator based on the phase current imbalance observed by the second control loop.

15. The controller according to claim 1, wherein the first control loop comprises a proportional-integral-derivative PID controller, wherein the first set of coefficients comprises: The first proportional coefficient for the proportional term of the PID controller, the first integral coefficient for the integral term of the PID controller, and the first derivative coefficient for the derivative term of the PID controller; and The second set of coefficients includes: a second proportional coefficient for the proportional term of the PID controller, a second integral coefficient for the integral term of the PID controller, and a second derivative coefficient for the derivative term of the PID controller.

16. The controller of claim 15, wherein the first proportional coefficient is calculated as P / (Vin The first integral coefficient is calculated as I / Vin, and the first derivative coefficient is calculated as D / (Vin). n), the second proportionality coefficient is calculated as P / (Vout) swp), the second integral coefficient is calculated as I / (Vout) swp), and the second derivative coefficient is calculated as D / (Vout) n swp), where n is the number of active phases of the multiphase switching voltage regulator, Vin is the input voltage of the multiphase switching voltage regulator, Vout is the output voltage of the multiphase switching voltage regulator, swp is the number of clocks in the switching cycle, P is the programmed proportional term, I is the programmed integral term, and D is the programmed derivative term.

17. A voltage regulator system, comprising: Multiphase switching voltage regulator; as well as A controller, configured to control the multiphase switching voltage regulator, the controller comprising: The first control loop has a first set of coefficients for implementing pulse width modulation (PWM) and a second set of coefficients for implementing pulse frequency modulation (PFM); and The second control loop is configured to achieve phase current balance for the multiphase switching voltage regulator. In the first configuration, the first control loop is configured to use the first set of coefficients to implement PWM-based control of the multiphase switching voltage regulator. In the second configuration, the first control loop is configured to use the second set of coefficients to implement PFM-based control of the multiphase switching voltage regulator.

18. The voltage regulator system of claim 17, wherein the first control loop comprises: A voltage-mode controller is configured to generate a current control signal based on a voltage error signal representing the difference between a reference voltage and the output voltage of the multiphase switching voltage regulator; as well as Current-mode controller In the first configuration, the current-mode controller is configured to generate a pulse-width modulation adjustment signal based on a current error signal derived from the current control signal, using the first set of coefficients. In the second configuration, the current-mode controller is configured to generate a pulse frequency modulation adjustment signal based on the current error signal using the second set of coefficients.

19. The voltage regulator system of claim 17, wherein the first control loop includes a voltage mode controller, wherein in the first configuration, the voltage mode controller is configured to generate a pulse width modulation adjustment signal based on a voltage error signal using the first set of coefficients, and wherein in the second configuration, the voltage mode controller is configured to generate a pulse frequency modulation adjustment signal based on the voltage error signal using the second set of coefficients, the voltage error signal representing the difference between a reference voltage and the output voltage of the multiphase switching voltage regulator.

20. The voltage regulator system of claim 17, wherein the first control loop comprises a proportional-integral-derivative PID controller, wherein the first set of coefficients comprises: The first proportional coefficient for the proportional term of the PI controller, the first integral coefficient for the integral term of the PI controller, and the first derivative coefficient for the derivative term of the PI controller; and The second set of coefficients includes: a second proportional coefficient for the proportional term of the PI controller, a second integral coefficient for the integral term of the PI controller, and a second derivative coefficient for the derivative term of the PI controller.

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